CNC plasma table thread! 5x10 Premier

ok software/CNC users if any, need a little help...
When I go to "motor tuning" in Mach 3 and tune the motors (they need to be fine tuned) i get them sounding really good, they move really smooth and cut soooo much better BUT the pieces come out bigger than the size that it's drawn?!?!
I think/guess it's because I'm changing the "steps per inch" therefor that's why????
So then I go to "Axis Calibration" in Mach 3 after motor tuning which I found out will calibrate and fix this issue BUT this is when things go backwards, cause now it will set the motors back to original "steps per unit" where 5" moves 5" but now my motors are back to moving slower, not as precise, don't sound right and doesn't cut as good especially on sharper corners/radius.
Is there something I'm overlooking here? Changing the "acceleration" and "velocity" of the motors will remain after doing the "axis calibration" but that doesn't help me out, it's the "steps per unit" that I need to stay at what I set them at but be able to maintain the size of the drawing... Thank you for any help
Otherwise, table is cutting great on big stuff but the motors are "stepping"/"hopping" along rather than moving smoothly when cutting slower speeds and corners since it won't allow me to keep the "steps per unit" at what I want to set them at.
I hope I made sense of all this....
 
I have never directly used a CNC or know this software, but I have used a lot of planar axis devices with stepper motors and can guarantee that if you monkey with a "steps per inch" setting then it will definitely change the size of what your cut is.

When you say the cuts are not as precise what do you mean?
 
RatLabGuy said:
When you say the cuts are not as precise what do you mean?
Click to expand...
I'm doing a lot of research right now lol
Basically if I drew a 5x5 square it will cut it out like 6.5x6.5ish...until I did the "axis calibration" which then Mach 3 puts the "steps per inch" back to where it says it should be and it will cut the right size out then...hope that made sense
From what I'm reading just now, your right If I change the steps per unit it will change the size of the cut....bummer cause the motors sound awesome and run soo smooth when I put the "steps per inch" from 1374 to 2000 but that's where the cuts get off on measurements so Mach 3 will calibrate it back to 1374....
 
with the motors set to "1374 steps per inch" they are kinda jumpy/jerky when doing slow cuts, especially anything circular so that's why I started messing with motor tuning and that made a world of difference but then he cuts are off measurement....hmm back to reading
 
Then it sounds like you need to manually adjust or set the speed or acceleration settings independently, without bothering the steps per inch.
 
If you just want them to sound better and be more accurate, it depends on your stepper drivers but you can change the steps per rev on the driver itself to something higher then go back into axis calibration in mach and calibrate the steps per unit. Which is per inch. There is a point where your machine won't be able to keep up with the steps though when it's moving fast so there's an upper limit on microstepping and acceleration/rapid speed. Since you've got no positional feedback it will lose track of where it actually is and you'll have to slow it down some.
 
braxton357 said:
If you just want them to sound better and be more accurate, it depends on your stepper drivers but you can change the steps per rev on the driver itself to something higher then go back into axis calibration in mach and calibrate the steps per unit. Which is per inch. There is a point where your machine won't be able to keep up with the steps though when it's moving fast so there's an upper limit on microstepping and acceleration/rapid speed. Since you've got no positional feedback it will lose track of where it actually is and you'll have to slow it down some.
Click to expand...
Thanks I'll keep fiddling with it
 
Also am I supposed to have the CNC torch by itself suspended away from other wires or is it ok in the same loom
 
Wow just wow..glad I decided to take motors off..
These 2 motors had pinion screws stupid loose...
1633445712084997592136457730401.jpg


Then this X axis was not aligned properly with each side..as soon as I disconnected 2nd motor it sprung forward about 1.2"..holy cow.
16334458398975472751441192901945.jpg



Looks like today is table maintenance and double check all previous owner connections. Going to add bracing to the gantry too
 
WARRIORWELDING said:
I've never saw a machine that did such a good job mimicking free hand work! Careful you might destroy a nitch, LOL.:lol:
Click to expand...
No kidding right, man I'm soooooo relieved
 
Ahhh heck yeah baby..3/8" plate is finally getting cut..not too shabby ..what say ye
20211008_134915.jpg
20211008_134922.jpg
20211008_134927.jpg
 

Attachments

  • 20211008_134932.jpg
    20211008_134932.jpg
    143.5 KB · Views: 64
So this is with 40amp tips..do you guys think with the proper 60amp tip it would get it that much better (I don't have any 60a tips right now)
1633719258710471891016173793944.jpg
16337192900281812145509546761133.jpg
 
forgot to mention, not everything "cheap" out there is cheap.
These 3/8" plates are being cut with $10 tips off Amazon...that's right, 10 tips for 10 bucks WTH...so I took a chance and holy cow, I've cut almost half a sheet of 3/8" with 1 tip and it seems it could still keep going even though I'm changing it to not take a chance and I figured out my amps apparently is still too high.
Learning the amperage setting on the plasma cutter has been my biggest challenge now lol, go figure. I thought 3/8 should be at 50+amps, closer to 60amp like I had it but come to find out, a 0.9mm Tip is 40amp and according to Everlast website and several forum users, the 0.9mm tip will cut 3/8 no problem with machine set to 40amps....that's crazy so that's exiting to get back to trying this out this weekend and see how that works out.
Needless to say, I'm about to order like 50tips from that company on Amazon, I mean Everlast gives you 5 for $74 so yeah, whatever......
 
Those are looking pretty good....cuts look clean on 40A. I would have assumed 60A for .375, but that seems to do the job pretty well.

One suggestion - you may be able to reduce/minimize that dross on the back of the part by increasing your cut speed a little. I know what's there is minimal and it probably chips away fairly easily with a chisel, but less post process time on your cut parts is more time you can stay under the hood...or more time to tell us how awesome this is. :lol:

Have you considered using lead-ins for your cut paths? That way you won't have a pierce mark right at the edge of your part. The pierce will be "off the part" then a lead-in (curved, straight....whatever your preference to the part geometry) will keep all your part edges clean and sharp.
 
Scooter402 said:
Those are looking pretty good....cuts look clean on 40A. I would have assumed 60A for .375, but that seems to do the job pretty well.
Click to expand...
oh no no this was at 60amp lol, i was saying I found out I only should be cutting at around 40a with the tips I have.
The dross will probably go away more once I turn down the amperage cause that's been my issue this whole time lol, I usually start with too high of amps then I figure out to turn that sucker down.
and I have lead-in, but on that straight line where you bend that bracket it should be straight pierce.
Tomorrow I will continue playing with cut speed and amperage to get this thick stuff cutting optimal ...i gotta empty the table of this 3/8 sheet cause now I have my 1st 2 orders of fire pits...woo hoo
 
@marty79 what is happening with all of the parts you are making? This is a lot of tabs. Are you supplying them to somebody?
 
RatLabGuy said:
@marty79 what is happening with all of the parts you are making? This is a lot of tabs. Are you supplying them to somebody?
Click to expand...
nope lol...they will be donated to whomever i guess. they look great and very usable but the 5/8 hole is not perfect so can't sell em, oh well
 
the front side of the 5/8" holes are perfect but as you go through, they are off a little so will have to be drilled out/reamed out and probably use "weld washers" maybe...
 
If soem fab shop could use them, surely teh small time in drilling the holes would be worthwhile
 
marty79 said:
the front side of the 5/8" holes are perfect but as you go through, they are off a little so will have to be drilled out/reamed out and probably use "weld washers" maybe...
Click to expand...
Sounds like the same quality of parts @Mac5005 got with his buddies box buggy, might as well sell them :lol:
 
Back
Top